A critics' darling turned sore disappointment, Showtime's spy drama is once again clicking on all cylinders. (Spoilers ahead if you're not caught up.)

When CIA station chief Allison Carr (Miranda Otto) attempts to flee Berlin, she employs the same tradecraft as the woman responsible for her capture. In “The Litvinov Ruse,” from the fifth season of Showtime’s “Homeland,” as we watch Allison, a Russian mole, cross crowded intersections and weave through the Hauptbahnhof—each image an emblem of the state’s omnipresent surveillance—Carrie Mathison (Claire Danes) recognizes the work of a fellow professional. Allison ditches her phone and twice switches platforms, Otto’s impassive face reflecting the interlude’s restraint: As a German agent remarks, “She’s a very cool customer,” and it’s this sense of control that defines “Homeland” itself.

Five years on from its acclaimed debut, having abandoned the absurdities of Carrie’s relationship with Sgt. Nicholas Brody, “Homeland” has become a series of slighter ambition and more assured execution, a pitch-black portrait of the War on Terror as focused on the moral hazard of American might as it is on Al Qaeda or ISIS. “The Litvinov Ruse,” like the fourth season’s masterful “There’s Something Else Going On,” is the culmination of the series’ newly patient, even workmanlike, plotting; Allison’s cat-and-mouse with Carrie, Saul (Mandy Patinkin), and their German allies is not the result of narrative fireworks, but of respect for the genre’s most elemental craft. Here, shifting from hidden cameras and airborne drones to Allison’s fast-moving fingers, or earlier, as Saul plants a bug in her purse under cover of darkness, “Homeland” offers a spare, tense treatment of its subject, and in turn the war’s worst compromises are made clear. “You can’t atone for that much blood, that many souls,” Carrie confesses. “Absolution is not available.”

Strange, then, that “Homeland”—nominated for four Emmys, including Drama Series and Actress (Drama)—should garner the TV Academy’s attention for the fifth season’s most controversial episode, one that also seems at loggerheads with the series’ recent strengths. Creators Howard Gordon and Alex Gansa (“24”) and Gideon Raff, of the Israeli series, “Prisoners of War,” on which “Homeland” is based, are no strangers to criticism, but the appearance of Arabic graffiti reading “‘Homeland’ Is Racist” in “The Tradition of Hospitality,” nominated for Cinematography (Single-Camera) and Directing (Drama Series), reanimated the most consistent rebuke of the series: That it is, to quote the headline of one appraisal, “the most bigoted show on television.”

Miranda Otto in “Homeland”

Showtime

Though it gestures at its own doubts as to the West’s humanitarian convictions, in the form of grandstanding German philanthropist Otto Düring (Sebastian Koch), “The Tradition of Hospitality,” much of which takes place in a refugee camp near the Syrian-Lebanese border, does in fact depict the residents as a teeming, faceless mass, mere set dressing for the climactic attempt on Carrie’s life. Coupled with the rather shortsighted perspective of a German intelligence official (Nina Hoss), who explains that “It’s not what they’re doing over there that scares us, it’s what happens when they come back,” the episode is an awfully soft target for the arguments against “Homeland”: Its sole purpose seems to be the brief, unremarkable action sequence that catalyzes Carrie’s season-long investigation.

With its interrogations, suicide bombers, and improvised explosive devices, “The Tradition of Hospitality” might demonstrate Emmy voters’ interest, dating back to the premiere of “24,” in espionage dramas with a hard-nosed, patriotic bent—the Jack Bauer school of diplomacy—but the episode’s nominations nonetheless suggest a misreading of the fifth season’s main thrust. As Allison’s tradecraft in “The Litvinov Ruse” suggests, the crisis in Syria and the rise of ISIS are products of American, Russian, and European policies, and not simply problems for those policies to confront; though their motives differ, she and Carrie, colleagues in Iraq after the fall of Saddam Hussein, adhere to the same rules of engagement. “She’s tearing it down,” Carrie says in the midst of Allison’s escape. “Exactly what I’d be doing right now if I were her.”

In these tactical echoes among Americans and their adversaries, carried over from its fourth season, the new “Homeland” unsettles the wider War on Terror’s simple binaries in favor of a bleak, at times desperate, acknowledgment that the blow is inextricable from the “blowback,” that fifteen years of fighting has brought us no nearer to peace. Even the thwarted attack is, as the title of the season finale has it, “A False Glimmer”: the justification for stricter limits on liberties, for bombing campaigns and proposed Muslim bans, for actions that breed more of the fear and violence those actions are designed to stop.

The reinvention of “Homeland,” then, is not a return to the daring shape of the series’ first season, but a re-engineering of its very premise. “I missed something once before,” Carrie told Saul then. “I won’t… I can’t let that happen again.” Now, despite her success in foiling a sarin gas attack on the Berlin subway, she seems as resigned as the rest of us. “If that weapon had gone off, we’d be living in a different world today,” Saul says in the season finale. “We’re already living in a different world,” she replies. “The attack wasn’t the first, and it certainly won’t be the last.”